基于快速上下文切换扩展的快速地址空间切换

Fast Address Space Switch Based on Fast Context Switch Extension

在传统的x86处理器上进行地址空间切换通常需要清空TLB和cache,导致内核时间大量消耗。通过启用ARM920T嵌入式处理器上的快速上下文切换扩展机制,使每个进程地址空间中的低端32 MB可以被硬件重定向到该进程标志符指定的一段虚拟地址空间。该虚拟地址空间互不重叠,使得在进程切换时TLB和cache中的地址信息保持有效,消除了不必要的TLB和cache清空操作,提高了嵌入式系统的性能。

On traditional x86 processors,address space switch usually requires flushing Translation Look-aside Buffer（TLB） and cache,which consumes much kernel time.With Fast Context Switch Extension（FCSE） mechanism on ARM920T embedded processors,the lower 32 MB of address space is redirected to the segment specified by process identifier.These segments are never overlapped,so that address information stored in TLB and cache keeps valid during process switching.Unnecessary flushing of TLB and cache is eliminated,and embedded system performance is improved.